1. Field of the Invention
The present invention relates to a method for forming a micro pattern, and more particularly, to a method of forming a micro pattern capable of improving the uniformity of the critical dimension and a pattern shape in a photolithography process and improving the uniformity of the critical dimension and a pattern shape in an etch process accordingly, by improving a pattern abnormality phenomenon occurring in a micro contact formation process using RFP (resist flow process).
2. Background of the Related Art
As the semiconductor devices are higher integrated and the design rule are narrowed, RFP (resist flow process) has been employed in order to implement a contact pattern of a high resolution of below 0.14 μm and enhance formation of the pattern. The RFP is a process used to enhance a high resolution in the exposure equipment. This process includes reducing the size of a contact pattern by heating the contact pattern that was already exposed and formed at a given temperature of over a glass transition temperature of the photoresist film for over a given time, so that flow of the photoresist film is caused. However, during the RFP, if it exceeds an adequate temperature, i.e., temperature higher than the glass transition temperature and an adequate time, the photoresist film excessively flows, so that overhang that the photoresist film pattern is warped occurs. As a result, this makes it impossible to obtain a desired contact pattern in a subsequent etch process.